Marko Pjaca and Dani Alves come on to lead Juventus past Porto

Juventus inflicted a first home defeat on Porto this season with a mix of maturity and composure to seal an excellent 2-0 result in the first leg of the teams round-of-16 tie.

A moment of sheer madness in the 27th minute saw Alex Telles sent off for two horrendous challenges, leaving the Portuguese side with only 10 men. Since that moment, Porto sought only to defend deep and in numbers to block Juventus from getting an away goal, while neglecting their offensive duties.

Lacking in ideas and playing at a tempo that would impress even the most patient of turtles, Juve struggled to penetrate as Porto closed off all the spaces. Massimiliano Allegri sought to change the game with his substitutions and both the newly introduced Marko Pjaca and Dani Alves did just that. The duo scored one goal each by pouncing on defensive errors to finish perfectly and seal the win.

Positives

There is nothing better than boasting a tactician on the sidelines who not only reads the game perfectly but understands how to make the most of his entire squad. Moments after Allegri introduced Pjaca on to the pitch the Croatian scored while Alves managed another a minute after coming on. Allegri made the perfect changes at the exact right time to seal victory.

Negatives

Juventus have to show greater urgency at certain moments and learn how to speed up their passing game when sides sit deep with the intention of blocking them. While they must be commended for their patience and overall control, having five attack-minded players on the pitch ought to guarantee an abundance of ideas and quicker movements.

Player ratings (1-10; 10=best; players introduced after 70 minutes get no rating):

GK Gianluigi Buffon, 6 -- A spectator for the near entirety of the match as Porto sought to defend deep and neglect their attacking game.

DF Stephan Lichtsteiner, 6 -- He may not be the most refined on the right, but his warrior-like mentality makes it hard not to appreciate the player who runs relentlessly, creating an outlet for passes from the back. Just doesn't always provide the necessary quality.

DF Andrea Barzagli, 6 -- Only just back from injury yet as composed and assured as ever, commanding the defence with confidence.

DF Giorgio Chiellini, 6 -- A little flustered at the start of the match, but was then allowed to relax as Porto gave up their attacking game.

DF Alex Sandro, 7 -- Delicious crosses, the Brazilian created more chances than anyone on the pitch, picking out Alves for the second goal. Commanded the left lane as brilliantly as always and recovered possession frequently.

MF Sami Khedira, 6 -- If only the player could finish he would have at least managed one goal tonight. His reading of the game ensures he's always in the right place at the right time, but he rarely finishes off his chances.

MF Miralem Pjanic, 6 -- A passing machine, he sprayed the ball all over to initiate attacks and read the game beautifully.

MF Juan Cuadrado, 6 -- Ran a lot but he is as frustrating as he so often is. Capable of those moments of magic but more often than not is guilty of poor decisions and inaccuracy.

Marko Pjaca made no mistake when Porto's Miguel Layun gifted him a wide open shot from 12 yards out.

MF Paulo Dybala, 6 -- Had an excellent chance to open the scoring but he hit the post. His movement was good but struggled to really impose his talent. In and out of the game.

MF Mario Mandzukic, 6 -- Always happy to support Alex, contributing everywhere he can to ensure balance but offered little going forward. Not the best of games.

FW Gonzalo Higuain, 6 -- Worked immensely hard but as predicted, he was well shackled by the Porto defence that defended deep. Never gave up on the goal and very nearly scored a beautiful goal.

Substitutes:

MF Marko Pjaca, 7 -- Sensational way to announce himself by scoring his debut goal. Miguel Layun may have made the mistake but Pjaca's finish was nothing short of brilliant -- one touch, outside of his foot, goal. The Croatian introduced pace and speed of thought to make an impact on the game.

DF Dani Alves, 7 -- The player came on to widen the game and latched on to a perfect cross from countryman Alex to finish superbly.

MF Claudio Marchisio, N/A -- Barely offered any time to make an impact.

Mina Rzouki covers Juventus and the Italian national team for ESPN FC. Follow her on Twitter: @Minarzouki.